Pirates blow up a yacht, inspiring a search for Spanish coins and threatening the dolphins.

The brother of a man Keith helped send to prison plans a deadly revenge.

Aphrodite goes into labor during a hurricane.

After a diving accident, Keith's dolphin speech-synthesizer dominates his dreams.

Dr. Keith Ricks returns to Florida to head an ocean research team...

Mike finds Maya living alone with no food or electricity; Sydney takes an unwelcome interest in the institute.

A mermaid is spotted from a newly bought submarine.

Unscrupulous characters kidnap Flipper for a Cuban hotel's dolphin show.

A surfer dazzles Maya; a benefactor has eyes for Keith.

Reluctant, kidnapped Flipper is scheduled to perform for Castro.

Mike and Maya inadvertently bring back a deadly virus from forbidden Monkey Island.

Tracking devices indicate Flipper was responsible for two attacks on humans.

An environmental terrorist targets the institute.

Keith and his brother, Sandy, battle shark poachers.

Pam, Keith and Flipper discover criminals with genetically engineered oysters.

Criminals want to salvage a nuclear missile from the ocean floor.

After an underwater photographer and her pet moray turn up, so do a couple of corpses.

After contacting pollutants, a sick dolphin strands itself near the institute.

Mike tries to reunite his parents; an echolocation experiment fails.

A philandering wife and her lover frame a tuna fisherman for dolphin-clubbing.

Flipper and Pam try to help a plane-crash survivor.

A hotel owner seems unconcerned about sharks swimming near the beach.